Crosses are supposed to make us cower in fear and some believe they actually burn us. First of all how would you know that that particular vampire is a Christian or Catholic? They could be Jewish or Muslim or Satanic or Native American...well you get the picture.
The truth about this myth is we feel uncomfortable in any church because all of the worshippers focusing on one thing like their cross or minister leaves latent energy laying around that is unfocused and creates ley lines.
We feel drained and hungry if we remain inside of any church for too long but this is not because we are evil.
Some think that we are abominations because of this but let me point out for all the religous people out there that God created everything and that includes us so we are no more evil than a wolf or cougar is.
God created us for a reason and who is to say that they have the knowledge or the right to second guess God.
The cross itself doesn't hurt us in any way unless it is made of silver (silver is an inhibitor) and we are wearing it, then it weakens our abilities; however, we do have a problem looking at gold.
We will look at anything but the gold and when someone is wearing a gold cross we avoid them, but this cross would not harm us. I HAVE seen cases where a silver or gold cross blessed by a priest has burned a vampire that tried to wear it for more than a few minutes. I don't know if this is a psychological thing or a physical thing.